Cancellable

public protocol Cancellable

Represents a cancellation handler over an asynchronous operation. Cancellation may be immediate or simply requested to happen sometime in the future.

A typical usage for Cancellable is to return it from the asynchronous completion-based API.

let cancellable = asynchronousFunction(completion: completion)
if shouldCancel {
   cancellable.cancel()
}

Note

Cancellable implementation must support thread-safety and guarantee that after calling cancel() the cancellation happens only once.
  • Cancels scheduled operation or does nothing if the operation is finished before the call.

    Note

    Subsequent calls shouldn’t do anything.

    Declaration

    Swift

    func cancel()